Building-related Symptoms Research Articles

Indoor air quality, ventilation and health symptoms in schools: an analysis of existing information

We reviewed the literature on Indoor Air Quality (IAQ), ventilation, and building-related health problems in schools and identified commonly reported building-related health symptoms involving schools until 1999. We collected existing data on ventilation rates, carbon dioxide (CO2) concentrations and symptom-relevant indoor air contaminants, and evaluated information on causal relationships between pollutant exposures and health symptoms. Reported ventilation and CO2 data strongly indicate that ventilation is inadequate in many classrooms, possibly leading to health symptoms. Adequate ventilation should be a major focus of design or remediation efforts. Total volatile organic compounds, formaldehyde (HCHO) and microbiological contaminants are reported. Low HCHO concentrations were unlikely to cause acute irritant symptoms (<0.05 ppm), but possibly increased risks for allergen sensitivities, chronic irritation, and cancer. Reported microbiological contaminants included allergens in deposited dust, fungi, and bacteria. Levels of specific allergens were sufficient to cause symptoms in allergic occupants. Measurements of airborne bacteria and airborne and surface fungal spores were reported in schoolrooms. Asthma and 'sick building syndrome' symptoms are commonly reported. The few studies investigating causal relationships between health symptoms and exposures to specific pollutants suggest that such symptoms in schools are related to exposures to volatile organic compounds (VOCs), molds and microbial VOCs, and allergens.

Building-related symptoms and molds: a two-step intervention study.

To evaluate the relation between mold growth and symptoms in an intervention study design. The building was examined by a walk-through and microbiological testing from surfaces and ventilation canals before and after each of two steps of the renovation. The examination program for the 25 employees comprised questionnaire, clinical examination, 2-week peak-flow monitoring, and blood samples, and in six persons also a bronchial challenge. Initially the building had severe moisture problems with growth of Trichoderma and Phoma as dominating microfungi. The total number of symptoms from a nine-item building-related symptom score was 66%, peak-flow variability was 20%. After the first renovation, no visible mold growth was seen, but samples showed that the building was still contaminated. Symptoms decreased to 33%. After further cleaning the mold levels decreased on surfaces, and the number of symptoms decreased to 4%. Mean peak-flow variability fell to 15%. In a poorly maintained building with moisture problems and mold growth, the staff had a number of irritative and general symptoms. The first renovation eradicated most visible signs of molds and gave a decreased number of symptoms. The second renovation sufficiently cleaned the building, and the rate of symptoms and peak-flow variability fell to normal levels. A thorough cleaning after renovation seems necessary for the eradication of symptoms.

Improving the health of workers in indoor environments: priority research needs for a national occupational research agenda.

Indoor nonindustrial work environments were designated a priority research area through the nationwide stakeholder process that created the National Occupational Research Agenda. A multidisciplinary research team used member consensus and quantitative estimates, with extensive external review, to develop a specific research agenda. The team outlined the following priority research topics: building-influenced communicable respiratory infections, building-related asthma/allergic diseases, and nonspecific building-related symptoms; indoor environmental science; and methods for increasing implementation of healthful building practices. Available data suggest that improving building environments may result in health benefits for more than 15 million of the 89 million US indoor workers, with estimated economic benefits of $5 to $75 billion annually. Research on these topics, requiring new collaborations and resources, offers enormous potential health and economic returns.

Populations and determinants of airborne fungi in large office buildings.

Bioaerosol concentrations in office environments and their roles in causing building-related symptoms have drawn much attention in recent years. Most bioaerosol studies have been cross-sectional. We conducted a longitudinal study to examine the characteristics of airborne fungal populations and correlations with other environmental parameters in office environments. We investigated four office buildings in Boston, Massachusetts, during 1 year beginning May 1997, recruiting 21 offices with open workstations. We conducted intensive bioaerosol sampling every 6 weeks resulting in 10 sets of measurement events at each workstation, and recorded relative humidity, temperature, and CO2 concentrations continuously. We used principal component analysis (PCA) to identify groups of culturable fungal taxa that covaried in air. Four major groupings (PCA factors) were derived where the fungal taxa in the same groupings shared similar ecological requirements. Total airborne fungal concentrations varied significantly by season (highest in summer, lowest in winter) and were positively correlated with relative humidity and negatively related to CO2 concentrations. The first and second PCA factors had similar correlations with environmental variables compared with total fungi. The results of this study provide essential information on the variability within airborne fungal populations in office environments over time. These data also provide background against which cross-sectional data can be compared to facilitate interpretation. More studies are needed to correlate airborne fungi and occupants' health, controlling for seasonal effects and other important environmental factors.

Upper Respiratory Symptoms Associated With Aging of the Ventilation System in Artificially Ventilated Offices in São Paulo, Brazil

The increase of work-related respiratory complaints in artificially ventilated buildings has multiple causes, and the role of allergen exposure and symptoms is still controversial. To analyze the risk factors and the association of work-related symptoms with allergen exposure and different conditions of the same air conditioning system in São Paulo, Brazil. Workers were classified according to characteristics of the air conditioning system: the first group (group 1) with ventilation machinery and ducts with > 20 years of use, the second group (group 2) with ventilation machinery with > 20 years of use and ventilation ducts with < 2 years of use, and the third group (group 3) with ventilation machinery and ducts with < 2 years of use. Logistic regression was performed to check the associations between air conditioning groups, allergen exposure (fungi, mites, animal dander, and cockroach), and symptoms. There was a higher prevalence of building-related worsening of respiratory symptoms (p = 0.004; odds ratio [OR], 8.53) and symptoms of rhinoconjunctivitis (p = 0.01; OR, 8.49) in group 1. There was a lower relative humidity (p = 0.05) and nonsignificant lower temperature in group 1, when compared to the other groups. The viable mold spores totals were higher outdoors than in the indoor samples (n = 45, p = 0.017). There were higher levels of Der p 1 in group 2 (p = 0.032). All allergen levels were considered low. There was a strong association of building-related upper-airway symptoms with places having ventilation systems with > 20 years of use.

Toxic-metabolite-producing bacteria and fungus in an indoor environment.

Toxic-metabolite-emitting microbes were isolated from the indoor environment of a building where the occupant was suffering serious building-related ill-health symptoms. Toxic substances soluble in methanol and inhibitory to spermatozoa at <10 microg (dry weight) ml(-1) were found from six bacterial isolates and one fungus. The substances from isolates of Bacillus simplex and from isolates belonging to the actinobacterial genera Streptomyces and Nocardiopsis were mitochondriotoxic. These substances dissipated the mitochondrial membrane potential (Deltapsi) of boar spermatozoa. The substances from the Streptomyces isolates also swelled the mitochondria. The substances from isolates of Trichoderma harzianum Rifai and Bacillus pumilus damaged the cell membrane barrier function of sperm cells.

Serum IgE specific to indoor moulds, measured by basophil histamine release, is associated with building-related symptoms in damp buildings.

To study the relationship between basophil histamine release (HRT) to indoor moulds, indicating specific IgE, and building-related symptoms (BRS), asthma, and hay fever in individuals working in damp and mouldy buildings. A cross-sectional study was performed among 86 school staff members, who on average had worked 143 months (range: 3-396) in moist buildings with mould growth in the constructions. A questionnaire concerning mucous membrane symptoms, facial skin symptoms, central nervous system symptoms, hay fever, and asthma was fulfilled by the participants, and blood samples were taken. Eight mould species growing on building constructions were identified and cultivated to obtain allergenic materials for testing. The presence in serum of IgE specific to moulds was verified by histamine release test (HRT) based on passive sensitization of basophil leukocytes. The validity of the method was confirmed by parallel testing of patients allergic to grass- and birch pollen and by the shift from positive to negative response after removal of serum IgE and by using sham sensitization. The prevalence of most BRS was between 32% and 62%. Positive HRT, showing serum IgE specific to one or more of the moulds, was observed in 37% of the individuals. The highest frequency of positive HRT was found to Penicillium chrysogenum and then to Aspergillus species, Cladosporium sphaerospermum and Stachybotrys chartarum. A significant association was found between most BRS and positive HRT, whereas no association was observed between positive HRT to moulds and self reported hay fever or asthma. Positive HRT to indoor moulds, showing the presence in serum of IgE specific to the fungi, was found to be related to BRS in individuals working in damp and mouldy buildings. Whether the association is of causal character is a question for further studies. The test may be useful in the evaluation and study of possible mould induced BRS.

Microbiology on indoor air '99--what is new and interesting? An overview of selected papers presented in Edinburgh, August, 1999.

A multidisciplinary approach to microbiological implications of indoor air is fruitful for research as well as management of health and building problems. The Finnish and the Danish mold programs are examples of such productive collaborative studies. Dust samples taken from classrooms in schools where occupants complain of building-related symptoms (BRS) demonstrated an inflammatory potential in vitro, measured as a release of cytokine interleukin (IL)-8. An increase of the metabolite NO and liberation of tumor necrosis factor (TNF)-alpha and other cytokines during exposure were obtained in vivo, was presented based on these programs and on epidemiological studies on residential fungal contamination and health conducted in Canada and The Netherlands. New methods for assessing fungal exposure are PCA analysis for the toxigenic mold Stachybotrys chartarum and EPS-Asp/Pen for detecting of Aspergillus and Penicillium in dust. Based on a limited data set it is shown that emission rates of fungal spores are inversely proportional to relative humidity (RH), directly related to flow rate and to surface loading. Poor maintenance, risk constructions and risk materials are described in several studies as the main causes of water damage in buildings.

Particulate Matter Intervention Study: A Causal Factor of Building-Related Symptoms in an Older Building

Abstract Five floors of a 20-year old 6-story office building were investigated using an integrated step-by-step investigation strategy. This involved a walkthrough inspection, an occupant questionnaire, and targeted environmental monitoring of indoor air quality and comfort parameters. The initial questionnaire survey revealed a high occurrence of building-related symptoms. The walkthrough inspection and environmental monitoring identified deposits of surface dust (indoor surface pollution – ISP) on carpets and hard surfaces, and elevated levels of carbon dioxide and respirable suspended particulate matter (RSP) throughout the building. An intervention study (blinded to the occupants) was targeted at reducing ISP levels by replacing normal carpet cleaning practices with higher performance vacuum cleaners and improved cleaning practices. The intervention reduced ISP levels and significantly lowered RSP concentrations by approx. 80% from initial values and against control floors. A follow-up SBS questionnaire revealed significant reductions in all but two of the symptoms. The most significant reductions occurred with symptoms of eye irritation, throat irritation, dry unproductive cough, and nose irritation. The study showed that in older buildings with poor ventilation, a build-up of ISP, and elevated RSP levels, using higher performance carpet cleaning practices can reduce RSP to acceptable levels and can reduce SBS symptoms.

Airborne Gram-negative Bacteria and Endotoxin in Sick Building Syndrome

During a survey of building-related symptoms among 1355 employees working in 19 governmental office buildings in the Netherlands, we measured physical and chemical factors, airborne microorganisms, and endotoxin. Mechanically ventilated buildings were grouped as "healthy" or "sick" based on symptom prevalence (mean symptom prevalence < 15% or > or = 15%). We compared physical, chemical, and microbiological characteristics between mechanically ventilated and naturally ventilated buildings. Gram-negative rods were found in higher numbers in the "sick" buildings. The concentration of airborne endotoxin was six to seven times higher in the "sick" buildings than in the "healthy" buildings (254 vs 46 ng/m3); it was 35 ng/m3 in naturally ventilated buildings. No differences in physical characteristics of the buildings were found. Volatile organic compounds and carbon dioxide were present at higher concentrations in naturally ventilated buildings. Airborne microbial contamination, in particular with gram-negative rods and perhaps with endotoxin, may have a role in the causation of sick building syndrome.

Psychological aspects of ″environmental illness,” ″multiple chemical sensitivity,” and building-related illness

Psychological aspects of ″environmental illness,” ″multiple chemical sensitivity,” and building-related illness

Psychological aspects of “environmental illness,” “multiple chemical sensitivity,” and building-related illness

Psychological aspects of “environmental illness,” “multiple chemical sensitivity,” and building-related illness

INVESTIGATION OF INDOOR AIR QUALITY COMPLAINTS

Objective conclusions regarding IAQ complaints in a large facility require a systematic investigation of both occupant health status and building conditions. Underlying causes of complaints may represent specific deficiencies in HVAC operation, excessive source emissions, or, alternatively, may involve factors unrelated to IAQ. Response to IAQ problems may involve changes in overall building conditions or efforts to manage hypersensitivity on an individual basis. Physicians knowledgeable in IAQ principles can play an important role in resolving occupant concerns regarding apparent building-related symptoms.

The Sick Building Syndrome in Office Buildings -- A Breath of Fresh Air

Complaints from office workers about building-related symptoms began to flood public health agencies during the late 1970s, in the wake of the energy crisis. The eye, nose, and throat irritation, headache, and difficulty concentrating that occurred in persons working in office buildings came to be called the sick building syndrome. Ventilation standards had been lowered to 5 ft3 (0.14 m3) of outdoor air per minute per person in 1975, and the new building-related symptoms were assumed to be attributable to lower rates of ventilation. In buildings with a high prevalence of sick building syndrome, the most common recommendation of . . .

The role of psychological factors in the report of building-related symptoms in sick building syndrome.

Sick building syndrome (SBS) is an increasingly common problem, although continued skepticism exists regarding its validity. Because of this, the attribution of complaints to psychogenic causes or mas hysteria persists. In this study (N = 111), self-report measures of psychopathology (Minnesota Multiphasic Personality Inventory [Hathaway & McKinley, 1983] and SCL-90-R [Derogatis, 1983]) and physical symptom reports failed to discriminate symptomatic from nonsymptomatic workers in an affected building but could more generally differentiate workers in the target building from control subjects. These results suggest that SBS cannot be justifiably attributed to psychological factors alone, although working in a contaminated environment appeared to have deleterious psychological consequences for some workers. Smoking history (in pack/years [packs per day x number of years smoked]) was reliably associated with the development of symptoms in exposed workers. Issues related to the assessment of psychological complaints in SBS are discussed.

The role of psychological factors in the report of building-related symptoms in sick building syndrome.

Sick building syndrome (SBS) is an increasingly common problem, although continued skepticism exists regarding its validity. Because of this, the attribution of complaints to psychogenic causes or mas hysteria persists. In this study (N = 111), self-report measures of psychopathology (Minnesota Multiphasic Personality Inventory [Hathaway & McKinley, 1983] and SCL-90-R [Derogatis, 1983]) and physical symptom reports failed to discriminate symptomatic from nonsymptomatic workers in an affected building but could more generally differentiate workers in the target building from control subjects. These results suggest that SBS cannot be justifiably attributed to psychological factors alone, although working in a contaminated environment appeared to have deleterious psychological consequences for some workers. Smoking history (in pack/years [packs per day x number of years smoked]) was reliably associated with the development of symptoms in exposed workers. Issues related to the assessment of psychological complaints in SBS are discussed.

Fall of the Pemberton Mill

Scientific literature and documents pertaining to the effects of inhalation exposure to carbon dioxide (CO2) on human health and psychomotor performance were reviewed. Linear physiological changes in circulatory, cardiovascular, and autonomic systems on exposure to CO2 at concentrations ranging from 500 to 5000 ppm were evident. Human experimental studies have suggested that short-term CO2 exposure beginning at 1000 ppm affects cognitive performances including decision making and problem resolution. Changes in autonomic systems due to low-level exposure to CO2 may involve these effects. Further research on the long-term effects of low-level CO2 exposure on the autonomic system is required. Numerous epidemiological studies indicate an association between low-level exposure to CO2 beginning at 700 ppm and building-related symptoms. Respiratory symptoms have been indicated in children exposed to indoor CO2 concentrations higher than 1000 ppm. However, other indoor comorbid pollutants are possibly involved in such effects. In the context of significant linear increase of globally ambient CO2 concentration caused by anthropogenic activities and sources, reducing indoor CO2 levels by ventilation with ambient air represents an increase in energy consumption in an air-conditioned building. For the efficient energy control of CO2 intruding a building from ambient air, the rise of atmospheric CO2 concentration needs to be urgently suppressed.